Kris HumphriesIndicted Scam Artist Jacked Me for $617K

12/8/2011 3:45 PM PST

Kris Humphries -- Indicted Scam Artist Jacked Me for $617K

Kris Humphries helped federal prosecutors get a grand jury indictment against a wedding guest who ripped him off to the tune of $617,000.

Andrey C. Hicks allegedly bilked more than $2.5 million from a total of 10 investors by telling them he was pumping their cash into a billion dollar hedge fund ... that didn't exist.

According to the indictment, Hicks instead blew wads of cash on a 2011 black Range Rover, 12 luxury watches, one diamond engagement ring, two pairs of earrings, another gold ring with diamonds, one pair of silver cuff links ... and one silver men's ring.

The docs show Humphries anted up his $617 grand to the alleged scammer on April 5. Four months later Hicks was sitting right behind Kris and Kim Kardashian at the rehearsal dinner for their massive wedding.

A rep tells TMZ Kris "has been working with law enforcement authorities" ... and doesn't want to comment further until the case is resolved.